From 81ad4276b505e987dd8ebbdf63605f92cd172b52 Mon Sep 17 00:00:00 2001
From: Zhang Rui <rui.zhang@intel.com>
Date: Fri, 18 Mar 2016 10:03:24 +0800
Subject: [PATCH] Thermal: Ignore invalid trip points

In some cases, platform thermal driver may report invalid trip points,
thermal core should not take any action for these trip points.

CC: <stable@vger.kernel.org> #3.18+
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1317190
Link: https://bugzilla.kernel.org/show_bug.cgi?id=114551
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
---
 drivers/thermal/thermal_core.c | 13 ++++++++++++-
 include/linux/thermal.h        |  2 ++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index a0a8fd1..d4b5465 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -454,6 +454,10 @@ static void handle_thermal_trip(struct thermal_zone_device *tz, int trip)
 {
 	enum thermal_trip_type type;
 
+	/* Ignore disabled trip points */
+	if (test_bit(trip, &tz->trips_disabled))
+		return;
+
 	tz->ops->get_trip_type(tz, trip, &type);
 
 	if (type == THERMAL_TRIP_CRITICAL || type == THERMAL_TRIP_HOT)
@@ -1800,6 +1804,7 @@ struct thermal_zone_device *thermal_zone_device_register(const char *type,
 {
 	struct thermal_zone_device *tz;
 	enum thermal_trip_type trip_type;
+	int trip_temp;
 	int result;
 	int count;
 	int passive = 0;
@@ -1871,9 +1876,15 @@ struct thermal_zone_device *thermal_zone_device_register(const char *type,
 		goto unregister;
 
 	for (count = 0; count < trips; count++) {
-		tz->ops->get_trip_type(tz, count, &trip_type);
+		if (tz->ops->get_trip_type(tz, count, &trip_type))
+			set_bit(count, &tz->trips_disabled);
 		if (trip_type == THERMAL_TRIP_PASSIVE)
 			passive = 1;
+		if (tz->ops->get_trip_temp(tz, count, &trip_temp))
+			set_bit(count, &tz->trips_disabled);
+		/* Check for bogus trip points */
+		if (trip_temp == 0)
+			set_bit(count, &tz->trips_disabled);
 	}
 
 	if (!passive) {
diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index 9c48199..a55d052 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -156,6 +156,7 @@ struct thermal_attr {
  * @trip_hyst_attrs:	attributes for trip points for sysfs: trip hysteresis
  * @devdata:	private pointer for device private data
  * @trips:	number of trip points the thermal zone supports
+ * @trips_disabled;	bitmap for disabled trips
  * @passive_delay:	number of milliseconds to wait between polls when
  *			performing passive cooling.
  * @polling_delay:	number of milliseconds to wait between polls when
@@ -191,6 +192,7 @@ struct thermal_zone_device {
 	struct thermal_attr *trip_hyst_attrs;
 	void *devdata;
 	int trips;
+	unsigned long trips_disabled;	/* bitmap for disabled trips */
 	int passive_delay;
 	int polling_delay;
 	int temperature;